1 /*
2  * Copyright (C) 2019 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 package com.android.compatibility.common.util;
18 
19 import static org.junit.Assume.assumeTrue;
20 
21 import android.content.res.Resources;
22 import android.text.TextUtils;
23 import android.util.Log;
24 
25 import androidx.annotation.NonNull;
26 import androidx.annotation.Nullable;
27 
28 import org.junit.AssumptionViolatedException;
29 import org.junit.rules.TestRule;
30 import org.junit.runner.Description;
31 import org.junit.runners.model.Statement;
32 
33 /**
34  * Custom JUnit4 rule that does not run a test case if the device does not define the given system
35  * resource.
36  *
37  * <p>The tests are skipped by throwing a {@link AssumptionViolatedException}.  CTS test runners
38  * will report this as a {@code ASSUMPTION_FAILED}.
39  */
40 public class RequiredSystemResourceRule implements TestRule {
41 
42     private static final String TAG = "RequiredSystemResourceRule";
43 
44     @NonNull private final String mName;
45     private final boolean mHasResource;
46 
47     /**
48      * Creates a rule for the given system resource.
49      *
50      * @param resourceId resource per se
51      * @param name resource name used for debugging purposes
52      */
RequiredSystemResourceRule(@onNull String name)53     public RequiredSystemResourceRule(@NonNull String name) {
54         mName = name;
55         mHasResource = !TextUtils.isEmpty(getSystemResource(name));
56     }
57 
58     @Override
apply(Statement base, Description description)59     public Statement apply(Statement base, Description description) {
60         return new Statement() {
61 
62             @Override
63             public void evaluate() throws Throwable {
64                 if (!mHasResource) {
65                     Log.d(TAG, "skipping "
66                             + description.getClassName() + "#" + description.getMethodName()
67                             + " because device does not have system resource '" + mName + "'");
68                     assumeTrue("Device does not have system resource '" + mName + "'",
69                             mHasResource);
70                     return;
71                 }
72                 base.evaluate();
73             }
74         };
75     }
76 
77     /**
78      * Gets the given system resource.
79      */
80     @Nullable
81     public static String getSystemResource(@NonNull String name) {
82         try {
83             final int resourceId = Resources.getSystem().getIdentifier(name, "string", "android");
84             return Resources.getSystem().getString(resourceId);
85         } catch (Exception e) {
86             Log.e(TAG, "could not get value of resource '" + name + "': ", e);
87         }
88         return null;
89     }
90 
91     @Override
92     public String toString() {
93         return "RequiredSystemResourceRule[" + mName + "]";
94     }
95 }
96